Combination stabilization and heeling system for cargo ships. ice breakers, and the like

ABSTRACT

1,063,410. Stabilizing ships. JOHN J. Mc- MULLEN ASSOCIATES Inc. Nov. 12, 1965 [Sept. 23, 1965], No. 48212/65. Heading B7M. A stabilization and heeling tank system (10), Fig. 1 (not shown), in a ship includes a rectangular tank (12) mounted transversely across the hull, a centre line bulkhead (14) dividing the tank (12) into two substantially equal volumed compartments and two spaced openings (70) in the bulkhead which extend through a major distance of the height of tank (12). The tank is filled to a predetermined level (90) with sea water, fuel or bunker oil and liquid transfer between the compartments is controlled by sliding doors (22) which are moved by cylinder-piston units (30). Pump means (52) communicating with the two compartments can also selectively move liquid from either one of the compartments to the other. One or more additional longitudinal bulkheads (42) having spaced cuts (44) and semicircular cuts (46) are provided in each compartment of tank (12). Sliding doors (22) may be replaced by doors rotatable about a vertical axis or about a horizontal axis.

June 27, 1967 s. B. FIELD 3,327,672

COMBINATION STABILlZATION AND HEELING SYSTEM FOR CARGO SHIPS ICE BREAKERS, AND THE LIKE Filed Sept. 25, 1965 3 Sheets-Sheet 1 IN VENTOR She/don 5. Field ATTORNEYS s. a. FIELD 3,327,672

AND THE LIKE June 27, 1967 COMBINATION STABILIZATION AND HEELING SYSTEM FOR CARGO SHIPS Filed Sept. 23, 1965 ICE BREAKERS 3 Sheets-Sheet 2 INVENTOR She/don B. F ie/a' ATTORNEYS 3,327,672 FOR 5. B. FIELD June 27, 1967 COMBINATION STABILIZATION AND HEELING SYSTEM CARGO SHIPS ICE BREAKERS AND THE LIKE 1965 3 Sheets-Sheet 5 Filed Sept. 23

Sha /don 8. Field ATTORNEYS United States Patent 3,327,672 COMBINATION STABILIZATION AND HEELING SYSTEM FOR CARGO SHIPS, ICE BREAKERS, AND THE LIKE Sheldon B. Field, Floral Park, N.Y., assignor to John J. McMullen Associates, Inc., New York, N.Y., a corporation of New York Filed Sept. 23, 1965, Ser. No. 489,713 Claims. (Cl. 114-125) between. A pump operates to force liquid from one compartment to the other when said doors and the like are closed whereby the system is adapted to operate as a passive stabilizer, an active stabilizer or a heeling tank.

One important feature of the present invention stems from my discovery that a greater heeling moment can be developed with one centerline door than the moment in systems using a three compartmented tank. Basically, theentire dimension of the compartment located outboard of the centerline bulkhead containing the door contributes to the heeling moment when, after the door is closed, the stabilizing medium is pumped into that compartment'. Since the moment being developed is greater than priorknown systems, the vessel will controllably change in an angular attitude at a rate faster than if the vessel were equipped with these prior known systems.

It is one primary object of the present invention to provide an elongated tank extending across the hull of the ship with a body of liquid partially filling said tank, a longitudinal bulkhead dividing said tank into two isolatable compartments only, said bulkhead having at least one enlarged" opening to enable the liquid transfer therethrough between said compartments, a movable door mova'bly mounted on said bulkhead and adapted to selectably, completely and partially open and close said opening depending upon its position relative thereto, and reversible pump means communicating with said two compartments for selectively moving liquid from one of said compartment-s to the other whereby when said dooris open and said pump means is off the system operates in the passive stabilization mode, and when the door is closed and the pump is on the system operates in a heeling tank mode.

It is another primary object of the present invention to provide a sliding door arrangement operated by hydraulic pistons in the system set forth above.

It is another object of the present invention to provide a system of the type described which includes additional longitudinal bulkheads mounted in each isola'table compartment, said additional bulkheads having a plurality of vertically extending cuts or slots through which the liquid transfers whereby kinetic energy of the transferring liquid is dissipated. These bulkheads are also provided with a plurality of air openings to insure an unimpeded transfer of -air between the subcompartments of the stabilizer.

i It is yet another object of the present invention to provide a system of-the type described which includes a movable plate having one edge thereof hingedly mounted to said center longitudinal bulkhead. Yet another embodiment of the present invention comprises a rotatable plate movable between a position in which said plate is parallel 3,327,672 Patented June 27, 1967 to the plane of the bulkhead opening and a position co planar with said bulkhead opening.

Yet another object of the present invention is to provide a vacuum pump in the system so that valves and the need for their operation are eliminated at the time the system is used in the heeling tank mode.

Other and further objects of the present invention will become apparent with the following detailed description thereof when taken in view of. the appended drawings in which:

FIGURE 1 is a perspective view, with parts broken away, of the combination stabilizer and heeling tank.

h FCIGURE 2 is a side elevation of the centerline bulk- FIGURE 3 is a top line 3-3 of FIGURE 2.

FIGURE 4 is a fragmentary sectional view along line 44 of FIGURE 2. 1

FIGURE 5 is a front elevation ofan additional longitudinal bulkhead having a plurality of vertical cuts or openings therein.

FIGURE 6 is a fragmentary sectional view taken along line 6-6 of FIGURE 5.

FIGURES 7- and 8 illustrate other embodiments of movable doors which in combination with the tank comprise the present invention.

Referring now to the drawings in detail there is illus trated the passive stablization and heeling tank system generally. indicated as'10 which includes an elongated substantially rectangular tank 12 which is mounted trans versely across the hull (not shown) of a cargo ship, ice breaker, ferry or other like vessel. The necessary stiffeners are welded to structural elements andv decks of the tank system and vessel. A centerline bulkhead 14, which is part of the-major framework of the ship, divides the tank 12 into two substantially equal volumed compartments. Bulkhead 14 is provided with two enlarged, spaced openings which extend throughout a major distance of the height of tank 12. These-enlarged openings enable liquid transfer between thecompa'rtments for the purpose to be described below. I

Referringnow to FIGURES 2 and 3, aframework 16 is welded on one side of said bulkhead 14 about the periphery of each enlarged opening. Anelongated U -shaped guide channel 20, which has a portionextending either fore or aft beyond the area of its respective opening-is bolted at the top and bottom of framework 16. Each pair of channels 20 slidably support an upstanding door 22 provided with rollers 24 which engage the front top surface of guides 20. See FIGURE 4. Do0r' 22 also has a forward vertical lip 26 which when door 22 is closed seats snuggly section-a1 plan view taken along within a U-shaped'fre'ceiving flange 8 mounted at the forward and inward side of frame 16. Door 22 is also provided with a rear lip 34 which extends 'beyond the back face of the plane thereof and cooperates wtih a rear flange 36,on the frame 16 to insure a liquid tight seal when door 22 is closed.

A hydraulic cylinder and piston unit 30 has its one end welded or otherwise secured 'to the sides of tank 12, and the piston is mechanically connected to door 22 by bracket 32. The cylinder-piston unit 30 functions to move door 22 between its open and closed position, and therefore, said unit 30 is'mounted parallel to the direction of the movement of the door and guide channels 20.

This sliding door arrangement affords great advantage in that the movement of the door is in a direction parallel to the'plane of the door so that the door when operated does not work against the liquid. This feature as well as the sliding support arrangement for the doors enables use of less expensive machinery to operate the doors as well as a lower power requirement for door operation. Also of importance is the fact that these sliding doors enable movement thereof between a completely open and a completely closed position in the minimum amount of time.

The transverse dimension of tank 12 is mathematically calculated taking into account the height and length thereof and the anticipated weight and roll characteristics of the vessel. If, for any reason, as in the case illustrated in FIGURE 1, the width of tank 12 is less than that required for the sliding door operation, a longitudinally (laterally with regard to the tank) extending small alcove 40 is provided to enable the necessary take up space for door 22.

One or more additional longitudinal bulkheads 42 are provided in each compartment of tank 12 and have therein a plurality of vertically extending spaced but aligned cuts 44 and a plurality of spaced semi-circular cuts 46 and 48 at the extreme top and bottom thereof respectively. These additional bulkheads 42 enable liquid transfer therethrough and serve to dissipate a part of kinetic energy therefrom. As better seen in FIGURE 6,

an elongated rod or wire 43 having a circular crosssection is welded to the additional bulkhead 42 and lines the periphery of each elongated vertical cut or opening therein. The circular shape of wire 43 serves to enhance liquid transfer through these openings.

The tank 12 is also outfitted with the conventional vents 48, and drain valves and piping system 50 which serve to selectively drain tank 12 when desired.

A controllable vacuum pump 52 having a predetermined suitable liquid flow rate capacity communicates with both compartments of tank 12 through pipes 54 and openings 56 in the floors of said compartments. Pump 54 is preferably a high speed centrifugal pump with a low level trip. With the use of reversible vacuum pump 52, there is no need to use valves either at the openings 56 or in pipe 54. Since vacuum pumps of this type are conventional and known in the art, further detailed description thereof is not considered necessary.

In operation, tank 12 is first filled to a predetermined level with any suitable liquid medium such as sea water, fuel, bunker oil, or the like. The level of liquid is selected so that the natural frequency of oscillation thereof is equal to the natural frequency of roll, of the ship. When used as a passive stabilizer, pump 52 is shut off and doors 22 are opened to their fullest extent thus exposing the entire enlarged openings in bulkhead 14 to enable the greatest liquid transfer therethrough. As the sea imparts rolling forces to the vessel, liquid within the tank 12 transfers through the enlarged openings in bulkhead 14 and the cuts in the additional bulkhead 42. The shifting mass of liquid imparts a moment to the vessel which is in opposition to the roll and, in this manner, stabilizes the vessel. As the liquid transfers through tank 12 kinetic energy thereof is dissipated due to the openings in bulkheads 42 and therefore the liquid movement is hydrodynamically damped. However, the air in tank 12 moves unimpeded and transfers freely through cuts 44 or semi-circular cuts 46.

When it is desired to use this system as an active stabilization system or in the heeling tank mode, the hydraulic piston and cylinder unit 30 are energized to thus force doors 22 along guide rails 20. When doors 22 are finally seated in their closed positions, the cornpartment of tank 12 are eifectively isolated from each other. Next, pump 52 is energized and forces liquid from either one of the compartments of tank 12 to the other. As liquid is taken from one compartment and fed to the other, the pressures in the comparments are equalized by air flow through vent 48 in the normal manner.

If the system is used on a freighter or ferry with rolling stock, the present invention can be used to set up a controlled list to match the dock level with one of the decks of the vessel. In this way, the loading and unloading time of the vessel is shortened and with the present invention the greatest heeling moment is imparted to the vessel in the shortest amount of time.

When the present invention is used on ice breakers and the like, another advantage of the'present invention becomes apparent. It is commonly known that on some occasions induced roll must be imparted to the ice breaker to loosen the vessel from floating ice. With the present compartmented system, the greatest heeling moment can rapidly be imparted to the vessel, and, because of the same structure, said moment can be reversed in the shortest amount of time.

Referring now to FIGURES 7 and 8, there is illustrated other arrangements which can be used in lieu of sliding door arrangement in the embodiment shown in FIGURE 1. In FIGURE 7, only one enlarged opening is provided in bulkhead 14 and mounted in the center of this bulkhead is a rotatable butterfly valve or plate with substantially the same dimensions as said opening. Specifically, vertical plate 60 is hinged along the centerline of the opening and is selectively driven by a hydraulic motor unit 62. Plate 60 is shown in the open position in FIGURE 7, that is, perpendicular to the plane of bulkhead 14. To close the opening, motor unit 62 rotates plate 60 to a position coplanar with said bulkhead 14.

In FIGURE 8, there is again a single enlarged opening in bulkhead 14 and plate 64 has one edge thereof hingedly secured to bulkhead 14 along one edge of the opening. Again, a hydraulic motor unit 66 is mounted on bulkhead 14 above the opening and moves plate 64 between an open and closed position through a series of mechanical linkages 68.

The operations of the embodiment shown in FIGURES 7 and 8 is the same as that described above.

It should be understood that other and further modifications can be made to the present invention without departing from the spirit and scope thereof.

What is claimed is:

1. An elongated combined passive stabilizer and heeling tank arranged across the hull of a freighter, ferry, ice breaker, or any other type of ship comprising an elongated tank extending across the hull of said ship, a body of liquid partially filling said tank to a level so that the tank liquid oscillation frequency is tuned to the roll of the ship and an air space above said body of liquid, means provided within the tank to selectively divide said tank into two isolatable compartments only, said means including a centerline bulkhead having at least one enlarged opening to permit liquid passage therethrough, a movable door movably mounted on said bulkhead for selectively, completely and partially opening and closing said opening depending upon its position relative thereto, air vent means communicating with each compartment to equalize the air pressure therein when said door is closed, and pump means communicating with the two compartments for selectively moving liquid from either one of said compartments to the other whereby when said door is open and said pump means is de-energized the system operates as a passive stabilizer andwhen the door is closed and the pump means is energized the system operates as a heeling system.

2. A system as set forth in claim 1 wherein the opening in the centerline bulkhead is large so as to impart little damping to liquid passage and wherein said tank further comprises at least one additional longitudinal bulkhead within each said compartment spaced from the nearest end of the tank to form a wing tank therewith and having a plurality of openings therein with a total area sufficient to substantially dampen the liquid movement within said compartment so that the tank liquid oscillation lags the roll of the ship.

3.' A system as set forth in claim 2 wherein elongated guide channels are mounted above and below said opening on one side of said centerline bulkhead, said door having a top and a bottom which slidably seats in said guide channels so that the direction of movement of said door is confined to the plane of said channels, a door operating unit connected to said door for moving said door 5 between a fully opened position and a fully closed position whereby said door, when in the latter position, completely blocks liquid transfer through said opening to thus isolate one said compartment from the other.

4. A system as set forth in claim 3 wherein said door further comprises rollers rotatably mounted thereto which ride on one surface of said guide, and wherein said door operating unit comprises a hydraulic piston and cylinder arrangement having one end'fixed with respect to the stabilizer and having the other end connected by means of a bracket to said door.

5. A system as set forth in claim 4 wherein a framework is mounted to said bulkhead about the periphery of said enlarged opening, said framework having a vertical U-shaped flange at the opposite side of said opening from said door, said door comprising an upstanding forward extending lip which, when the door is closed, seats in said flange to close said opening.

6. A system as set forth in claim 5 wherein said centerline bulkhead is provided with two such said enlarged openings, doors, channel guide members, framework and operating units and wherein said doors open toward the sides of said tank and the enlarged openings are positioned toward the inside of said doors, one side of said tank being provided with a transversely extending alcove in which one of said doors is at least partially disposed when in its open position.

7. A system as set forth in claim 2 wherein said door comprises a rotatable plate having at least one part thereof hinged to said centerline bulkhead.

8. A system as set forth in claim 7 wherein said plate is vertically disposed and has its center hingedly mounted to said bulkhead to define a vertical axis of rotation and is horizontally rotatable to a position perpendicular to the plane of said bulkhead when in the open position and to a position within the plane of said bulkhead when in a closed position, said plate having substantially the same dimensions as said opening.

9. A system as set forth in claim 7 wherein one edge of said plate is hingedly mounted to said bulkhead along one edge of the enlarged opening, said plate having substantially the same dimensions as said opening.

10. A system as set forth in claim 2 wherein said openings in the additional longitudinal bulkhead extend above and below the static liquid level of the tank liquid.

References Cited UNITED STATES PATENTS 2,077,143 4/1937 Carroll 114125 3,192,888 7/1965 Field 114-125 MILTON BUCHLER, Primary Examiner.

T. M. BLIX, Assistant Examiner. 

1. AN ELONGATED COMBINED PASSIVE STABILIZER AND HEELING TANK ARRANGED ACROSS THE HULL OF A FREIGHTER, FERRY, ICE BREAKER, OR ANY OTHER TYPE OF SHIP COMPRISING AN ELONGATED TANK EXTENDING ACROSS THE HULL OF SAID SHIP, A BODY OF LIQUID OSCILLATION FREQUENCY IS TUNED TO THE ROLL OF TANK LIQUID OSCILLATION FREQUENCY IS TUNED TO THE ROLL OF THE SHIP AND AN AIR SPACE ABOVE SAID BODY OF LIQUID, MEANS PROVIDED WITHIN THE TANK TO SELECTIVELY DIVIDE SAID TANK INTO TWO ISOLATABLE COMPARTMENTS ONLY, SAID MEANS INCLUDING A CENTERLINE BULKHEAD HAVING AT LEAST ONE ENLARGED OPENING TO PERMIT LIQUID PASSAGE THERETHROUGH, A MOVABLE DOOR MOVABLY MOUNTED ON SAID BULKHEAD FOR SELECTIVELY, COMPLETELY AND PARTIALLY OPENING AND CLOSING SAID OPENING DEPENDING UPON ITS POSITION RELATIVE THERETO, AIR VENT MEANS COMMUNICATING WITH EACH COMPARTMENT TO EQUALIZE THE AIR PRESSURE THEREIN WHEN SAID DOOR IS CLOSED, AND PUMP MEANS COMMUNICATING WITH THE TWO COMPARTMENTS FOR SELECTIVELY MOVING LIQUID FROM EITHER ONE OF SAID COMPARTMENTS TO THE OTHER WHEREBY WHEN SAID DOOR IS OPEN AND SAID PUMP MEANS IS DE-ENERGIZED THE SYSTEM OPERATES AS A PASSIVE STABILIZER AND WHEN THE DOOR IS CLOSED AND THE PUMP MEANS IS ENERGIZED THE SYSTEM OPERATES AS A HEELING SYSTEM. 